Over the past decades, numerous attempts have been made by the criminal justice system of the United States to improve the sentencing practice in the country. Throughout the said attempts, four fundamental philosophies have been formulated by the criminal justice system in justifying the application of punishment rehabilitation, incapacitation, deterrence, and retribution. Despite the numerous debates on the effectiveness of each of the aforesaid philosophies, the public all the same concur that the ultimate objectives of these diverging philosophies are equally the prevention of crime and the infliction of suffering on wrongdoers.
Retribution is the most common and oldest justification for punishing a wrongdoer. Retribution rests on the principle of just deserts, which argues that the harshness of the punishment must be in line with the seriousness of the crime (2006, p.257). Retribution is concern with the needs of the general public and is, therefore, not the same as revenge, which distinctively aims to satisfy the needs of the victim or victims.
In contrast, deterrence sends a message to potential wrongdoers that misbehaviors will not be accepted by society. Thus, in deterrence the objective of sentencing is to avert future crimes. Deterrence can either be general deterrence or specific deterrence. The impact of the threat of legal punishment in general deterrence is focused on the general public, while the impact of the actual legal punishment in specific deterrence is focused on those people already apprehended.
Incapacitation, on the other hand, ensures that as long as wrongdoers are serving their sentences they will not be a threat to society. In a direct statement justifying incapacitation as a form of punishment, academic political scientist James Q. Wilson said that evil people exists and there is no other realistic solution than to separate them from innocent people (2006, p.258). Many studies, however, have revealed that upon the release of wrongdoers they are generally more expected to perpetuate crimes than before they were incarcerated.
Finally, rehabilitation as a purpose of punishment has been acknowledged as the most compassionate sentencing strategy for many decades. This rehabilitative concept suggest that by taking wrongdoers away from their surroundings and by getting involved in modifying their characters and values they can be treated of their tendencies toward crime. However, the criminal justice system in the country is presently supportive of get tough incapacitating, deterrent, and retributive sentencing strategies and is abandoning many of the principles of rehabilitation (2006, p.259).

Factors in Determination of Each Specific Sentence
In making decision judges generally consider two indispensable factors more than others the severity of the crime and the aggravating or mitigating circumstances (p.265). With regard to severity, the punishment is expectedly harsher for the more serious crime. Judges have their individual methods of establishing the gravity of the offense, but most of them simply weigh up the conviction offense, which is basing the prison term on the felony for which the defendant was found guilty (2006, p.265). However, circumstances like mitigating or aggravating circumstances affecting the crime may induce a judge to modify a sentence so that it will be more accurate to the entirety of the crime.
Mitigating circumstances are situations attending the perpetration of a crime that may give reason for a lighter penalty (2006, p.266). For instance, it is a mitigating circumstance when an offender committed the crime under strong provocation, or when the offenders participation to the crime is insignificant, or when the offender did not have sound mind when he or she committed the crime. Aggravating circumstances, in contrast, are conditions attending the perpetration of a crime that may justify a more severe penalty (2006, p.266). Good examples of aggravating circumstances are when the crime involved several offenders and the defendant was the mastermind of the group, or when the victim was committed with treachery, or was treated with considerable cruelty by the defendant.

Debates Surrounding Capital Punishment
Since the earliest days of the United States capital punishment has played a major role in sentencing of criminals. People in favor of capital punishment claims that it is just deserts for the most violent of criminals, and argue that death is the only appropriate retribution against those who commit heinous crimes. Those who oppose, however, view the penalty as a form of revenge and have no deterrent effect. Opponents worry that the employment of capital punishment by the governments will encourage vengeance in the society. Thus, they believe that the retribution claimed by the supporters is simply another term for vengeance that will only generate additional bloodshed to the already troubled society (2006, p.275).
Furthermore, supporters of the capital punishment assert that the criminal justice system discourages potential wrongdoers from committing heinous crimes by executing convicted violent criminals. This principle was the main justification for the many executions carried out in the United States. Nonetheless, many social scientists assert that there is little statistical verification of the deterrent impact of the death penalty (2006, p.275).

Rationale
Without a doubt, vengeance is the major reason why some people support death penalty because of humans logical annoyance with murder and crime. Governments must, therefore, not permit vengeance to command public policy and must disregard the temptation of manipulating societys mistaken belief that the capital penalty will be a significant response to criminality. In addition, there is no valid evidence on the deterrent effect of death penalty. In Texas, for instance, where executions of death penalty between 1980 and 1990 were very prevalent, the capital punishment revealed no deterrent effect among the criminals (The New York Times, 1991). Obviously, irrational people who commit murder do not think or are incapable to think about the penalty of death before carrying out the crime.
The major focus of death penalty in recent years has significantly shifted from morality issue to issues on effectiveness and fairness of the punishment. Obviously, because of the strong factual evidence on the inappropriateness of death penalty, the executions in many states have considerably declined in the past years. In fact, 35 of the 38 States that previously authorized the death penalty now encourage their juries to enforce life sentence without parole instead of death sentence (2006, p.275). Therefore, it is without doubt that the arguments of the opponents have considerably influenced the sentencing decisions of the United States criminal justice system.